Idler pulleys are often used with timing belts or drive belts that may be used to transmit power. This can be accomplished by using a driver pulley and one or more idler pulleys. Idler pulleys are used as a component of a belt tensioner to change the direction of the belt or to maintain belt tension. In some instances, the pulley may serve as a wheel, gear, roller or the like.
Idler pulleys generally include a pulley shell or body having a belt-engaging surface and one or more bearings. The pulley shell may be mounted to a surface or tensioner arm of the belt tensioner. The pulley shell is rotatably connected to the tensioner arm by the bearing seated within the pulley shell. A belt is then trained around the belt surface of the pulley shell. The belt surface may be smooth, deep V-shaped, cogged or multi-ribbed, as examples. Generally, the pulley shell and the mounting surface contain an aperture shaped to engage a fastener, such as a bolt to provide clamping force and to aid in securing components of the belt tensioner together. The fastener is inserted through the bearing and the pulley shell into the mounting surface.
It is often desirable to secure the bearing in place to inhibit movement of the bearing relative to the pulley shell, e.g., due to vibration or axial loading during use. It may also be desired to prevent the bearings from being contaminated with dust and other particles from the machinery. Contamination of the bearing may cause increased wear and reduced performance.
Accordingly, it is desired to have a device that can be used to hold the bearing in place within the pulley and to prevent contamination of the bearings. It is also further desired that the device be easy to attach to the outer shell of the pulley.